Granzyme A lights a fire Cytotoxic T cells and natural killer cells use several strategies to kill infected or transformed cells. One such pathway entails the delivery of a family of serine proteases called granzymes to target cells through perforin-mediated pores to induce a form of programmed cell death called apoptosis. Zhou et al. show that granzyme A cleaves and activates gasdermin B (GSDMB), a central player in the highly inflammatory cell death process known as pyroptosis (see the Perspective by Nicolai and Raulet). GSDMB expression was highly expressed in some tissues and could be up-regulated by interferon-γ. Enforced expression of GSDMB in cancer cells enhanced tumor clearance in a mouse model, suggesting that this pathway may be a target for future cancer immunotherapies. Science , this issue p. eaaz7548 ; see also p. 943